湿度循环下黏质路基土回弹模量演化规律  

Influence of Moisture Content Change Cyclicity on Modulus Evolution Law of Cohesive Subgrade Soil

作　　者：李冬雪[1] 凌建明[1] 钱劲松[1] 王海林[1] 

机构地区：[1]同济大学道路与交通工程教育部重点实验室,上海201804

出　　处：《同济大学学报（自然科学版）》2013年第7期1051-1055,共5页Journal of Tongji University:Natural Science

基　　金：交通运输部西部交通建设科技项目(2011318493720)

摘　　要：历经多次干湿循环的路基土,其力学性能劣化现象非常突出,路基的路用性能也随之衰减.基于室内试验研究含水率周期性变化对路基回弹模量的影响规律.遵循现场测试含水率变化态势,利用"透水石渗水—静置—烘箱脱水—透水石渗水—静置—烘箱脱水……"一系列湿度循环来模拟现场路基土的含水率波动过程,同时测试其回弹模量.结果表明:黏质路基土回弹模量受含水率变化的影响非常明显,回弹模量随湿度循环次数的增大而减小;在相同的应力状态下,黏质路基土的平衡含水率越高,其回弹模量值对含水率的周期性变化越敏感,且回弹模量值趋于不稳定状态.After experiencing a repeated dry-wet cycle, the mechanical properties of the subgrade soil show irreversible changes. An indoor test was carried out to investigate the influence of the moisture content changes cyclicity on resilience modulus of the cohesive subgrade soil. And the extent of the resilience modulus attenuation of subgrade result in frequently dry-wet cycle was analyzed. A series of humidity cycle such as ＂water seepage under the permeable stone-- standing--oven dehydration＂ were repeated to imitate the scene of the subgrade soil moisture content fluctuation process. The resilience of subgrade soil was tested by the system of UTM. The results show that the moisture content changes cyclicity influences the resilience modulus of cohesive subgrade soil. The resilience modulus decreases against the increase of cycle times. On the same stress state, the higherthe equilibrium moisture content is, the more sensitive the resilience modulus changes are. As a result, the resilience modulus tends to be unstable.

关 键 词：黏质路基土 回弹模量 含水率 湿度循环 

分 类 号：U416.1[交通运输工程—道路与铁道工程]